Every thing about the car was acceptable, except when accelerating from 100 Km/h.
I stepped on the gas, the engine revved up to 5,000rpm then dropped down to the 2300 rpm or so that it was doing and then takes off smoothly.

Is this normal?
I imagine that the issue is the tranny is trying to kick down into a lower gear and the speed was too high initially and so it put it back in gear and then accelerated.

take it to a mechanic to get it checked out. if i had to guess it is air or fuel or exhaust related i would start looking at the air filter then i would try to clean the maf. but it could be a bad cat.

take it to a mechanic to get it checked out. if i had to guess it is air or fuel or exhaust related i would start looking at the air filter then i would try to clean the maf. but it could be a bad cat.

I wouldn't be surprised if it is the original air filter. Dealers seem to forget about them.
My brother has an '01 Grandam. Always taken it in for service at all the outlined times. One day, he decided to buy a fram for it. The filter looked to be the original one even though it now had over 60,000kms on it. It was plugged solid and dirt colored!

His rep said they tend to miss them. Typical of the service they offer him.

OK I see what you mean, I thought you were going from a dead stop. The only thing I can tell you is transmissions in the Ford Taurus are weak. Alot of people on this site refer to them as "made of glass". Do regular maintance and drive it easy and you should be ok. Don't jerk around on it too much or it will leave you stranded sooner or later. I have a 01 with 95k and so far I have had no problems with the transmission, but then again the 12 valve engine dosent have enough power to pass anyone so I just follow the leader LOL.